Automotive body panels have traditionally been made from mild steels. In an effort to decrease vehicle weight, aluminum alloy body panels have been increasing in popularity. The automotive and aerospace industries have focused primarily on the 5xxx and 6xxx series aluminum alloys, which are aluminum-magnesium and aluminum-magnesium-silicon alloys, respectively. The 5xxx and 6xxx series aluminum alloys may be shaped and processed by methods consistent with those of mild steel sheets.
Aluminum-zinc alloys of the 7xxx series at T6 or T7x tempers have strength similar to those of high and ultra-high strength steels and can achieve yield strengths exceeding 400 MPa. Unfortunately, T6 and T7x temper aluminum-zinc alloys cannot be conventionally stamped, as the alloys have little to no formability at room temperature.